Advanced Materials Research Vols. 163-167

Abstract: Two 1/6 scale core walls, including one RC core wall with steel tube-reinforced concrete columns and concealed steel trusses and one conventional RC core wall, were tested under eccentric horizontal cyclic loading. The load-capacity, ductility, hysteresis characteristics, stiffness, stiffness deterioration process, energy dissipation and damage characteristics of the two specimens were compared and discussed in this paper. It shows that the seismic performance of the RC core walls under combined action could be improved by setting the concealed steel trusses in the walls and using the steel tube-reinforced concrete columns as the boundary elements.

Abstract: The shear wall with concrete filled steel tube (CFT) columns and steel plate is a new kind of composite shear wall. In order to know its seismic performance and failure mechanism, six 1/5 scale specimens with the same shear span ratio 1.5, including 3 steel plate shear walls (SPSWs) with CFT columns and 3 reinforced concrete shear walls (RCSWs) with CFT columns and embedded steel plate, were tested under cyclic loading. The thickness of the steel plates in the shear walls changed from 2mm, 4mm to 6mm. Based on the experiment, the load-carrying capacity, hysteresis characteristics, ductility, stiffness degradation, energy dissipation and damage characteristics of the specimens were analyzed. Especially, the ratio of height to sectional thickness of the steel plates in the shear wall was considered. The result shows that both the SPSW with CFT columns and the RCSW with CFT columns and embedded steel plate have good seismic performance and are with important practical engineering value.

Abstract: The height of a complex supertall building is 250m. The central RC tube and peripheral SRC frame with two outrigger trusses are employed to resist vertical and lateral loads. It is classified as B grade complex tall building due to the structural characteristic. Due to the over-restriction and complexity of the super tall-building, Pushover Analysis is carried out in order to find it’s behaviors under rare intensity earthquakes. The analytical results demonstrate that the SRC supertall building with high level transfer story possesses good energy-consuming capacity, ductility and ideal yield failure mechanism under rare seismic excitation. Seismic performance of the SRC supertall building is evaluated through Capacity Spectrum Method and good results are obtained.

Abstract: In this paper, an optimal design process for high-rise building structures is presented based on cost-effectiveness criterion. Then, an optimal design of a complex high-rise building based on cost-effectiveness criterion is carried out by using the design process. A minimum life cycle cost and corresponding elastic inter story drift considering initial cost and damage cost as two separate objective functions are obtained by using genetic algorithm. Finally, fitting curves of life cycle cost, initial cost, damage cost and corresponding performance indexes are interpolated by using one-dimensional linear interpolation considering elastic inter story drift ratio as control performance indexes. And lots of life cycle cost designs and corresponding performance indexes of the separated objective function are given. The results show that the optimal design process is practical and optimal results are diverse, and can be chosen flexibly by owners.

Abstract: Genetic arithmetic operators in genetic algorithm be improved , and a hybrid genetic algorithm of a gradient algorithm combining with the genetic algorithm be given against to the defects such as premature，slow on convergence rate，weak in the ability of local search ，all these appeared on the progress of genetic algorithm's iteration. Analysis result indicate that not only strong on the local search capacity of gradient algorithm be exhibited but also strong on the general search capacity of genetic algorithm be combined based on the hybrid genetic algorithm ,which make phenomenon of premature avoid, and the rate of convergence be improved greatly. Concrete calculated example indicated that the hybrid genetic algorithm is an effective structural optimization method.

Abstract: Take a High-rise Residential Building in Wuhan as research object, in assigns the construction plan under the premise, the optical mathematics model of the shear wall is established. Based on research of structure dynamic characteristics, displacement, mechanic character, structure measure, uses the criterion method and the exhaustion method, design principle of board high-rise residential building is conducted from the optical of shear wall arrangement，furthermore, site condition and seismic precaution intensity influence to the optical structure is analyzed.

Abstract: To satisfy the geotechnical strength requirements and the serviceability requirements, types of foundation systems (such as shallow foundation, pile foundation and composite foundation) have been developed. Of course, the type of foundation system is determined by many factors such as ground condition, economy and environmental influence of construction. To cope with weak or compressible soils, the authors present a raft foundation system with walled and columniform soil improvement for multistory buildings, which is economical and environment-friendly. In this raft foundation system, different columniform soil improvements in size and depth are used, and the subgrade under the edge of the foundation is walled by soil improvement. It can effectively control differential settlement and prevent relative rising of the structure by adjusting the size and depth of columniform soil improvements according to the soil layer difference of geological situation under the building. We have performed series numerical analyses under two-dimensional plane strain condition to study the settlement behaviors of the composite foundation system, and its effects on controlling differential settlement and improving bearing capacity were verified for immediate condition. As a continuous research, consolidation settlement analyses are performed, the process of excess hydraulic pressure dispersion with time and the consolidation settlement development are studied in this paper.

Abstract: This paper discusses the unfolding form of the folding wing and its application to special UAV. The main investigations involve aspects such as unfolding process of the special UAV’s folding wing, contour structure of the complete unfolding, the choice of composite materials for the folding wing and its overall performance parameters. Modeling and dynamics analysis are made for all-composite wing through finite element analysis and calculating software. The unfolding process is also simulated. The result shows that the wing’s first-order frequency is low, second-order frequency and third-order frequency are close at different sweep angles. The wings are apt to happen flutter coupling in flutter analysis. With the continued folding of the wing, the wing’s natural frequency decreases significantly at different orders. The conclusions can provide effective basis for the study of wing rotational rate, unfolding time and impact action.

Abstract: Three natural graphite flakes (35, 50 and 80 mesh) were used as raw material. Exfoliated graphite (EG) was prepared by rapidly heating residue H₂SO₄-graphite intercalation compounds (RGIC) in a muffle and by irradiating it in a microwave oven, respectively. Results show that the exfoliation volume of EG decreases with decreasing the raw graphite particle size. Compared with muffle heating, microwave irradiation is more helpful for the exfoliation of RGICs, especially for the small particle samples.

Abstract: On the background of a long-span composite girder cable-stayed bridge with three pylons under construction for research, this paper establishes two models of the whole bridge by considering the structural geometric nonlinearity, material nonlinearity and interface slip effect in composite girder, one has stable cables between pylons but the other hasn’t, then comparatively studies the failure loads and structural internal forces of the two models to achieve effects of stable cable on the ultimate load-carrying capacity of the cable-stayed bridge. This research shows that the stable cables can strengthen the vertical stiffness of structure and obviously increase the failure load of the bridge, and the internal forces in main girder, middle pylon and stayed cables are smaller and their distributions are more reasonable under the failure load than those in the bridge with no stable cables, so the stable cables can effectively improve the ultimate load-carrying capacity of long-span composite girder cable-stayed bridges with three pylons.